An organic electroluminescent device (hereinafter “electroluminescent” is abbreviated as “EL”) is a device in which an organic luminescent medium layer obtained by stacking an organic carrier-transporting layer or an organic emitting layer is provided between a first electrode and a second electrode, and has been attracting attention as a self-emission type display device capable of emitting light with a high luminance at low-voltage driving.
The device structure of an organic EL device is divided into a bottom-emission structure and a top-emission structure according to the outcoupling direction of light generated in an organic emitting layer. In the top-emission structure, light is outcoupled from the upper part which is opposite to a glass substrate, in contrast to a related-art structure in which light is outcoupled through a glass substrate supporting an organic EL device (bottom-emission structure). This improves the aperture ratio with respect to an emitting part, whereby the luminance can be increased.
In an organic EL device having a top-emission structure, studies have been made to attain a high color reproducibility by using, as an upper electrode, a semitransparent cathode including a metallic thin film layer (light-reflective layer), whereby only light with a specific wavelength is intensified to be outcoupled outside an EL device due to multi-interference effects.
For example, an organic EL device is disclosed in which a light-reflective electrode, an organic luminescent medium layer including an organic emitting layer, and an electrode formed of a semitransparent metal layer and a transparent material are stacked such that the organic luminescent medium layer functions as a resonator part, and which satisfies the following formula when λ is the peak wavelength of the spectrum of light to be outcoupled (see Patent Document 1, for example)(2L)/λ+Φ/(2π)=m wherein L is an optical distance, λ is a wavelength of light to be outcoupled, m is an integer, Φ is a phase shift at the electrode, and the optical distance L is adjusted to be minimized.
A full-color display is disclosed in which a top-emission type organic EL device and a TFT array for enabling active matrix driving of the organic EL device are used in combination (see Patent Document 2, for example).
However, in the technology described in the Patent Document 1, the thickness of an organic luminescent medium layer provided between the opposing electrodes is small since the device is configured such that the optical distance L is minimized. As a result, a short circuit tends to occur between the two electrodes due to unevenness of the surface of the light-reflective electrode as well as the underlying structure, resulting in lowered production yield of the organic EL device.
Polishing the surface of the light-reflective electrode to make it smooth is known as a technique to prevent occurrence of a short circuit between the electrodes. This technique is effective in an organic EL device having a bottom-emission structure. However, in an organic EL device with a top-emission structure, in particular, in a display in which a top-emission type organic EL device is provided on a TFT array, as disclosed in the Patent Document 2, the above-mentioned technique may cause such disadvantages as destruction of the TFT array portion due to static charges generated during polishing.    [Patent Document 1] WO01/39554    [Patent Document 2] JP-A-2001-195008
The invention has been made in view of the above-mentioned problems, and an object thereof is to provide an organic EL color light-emitting apparatus realizing a high luminous efficiency while suppressing a short circuit between the opposing electrodes.